Extensible prop



Oct. 28, 1958 B. D. OLSON 9 EXTENSIBLE PROP Filed. May 11, 1955 2 Sheets-Sheet 1 INVENTOR ATTORNEY Oct. 28, 1958 Filed May 11, 1955 2 Sheets-Sheet 2 mlll INVENTOR m Eu -inc I I I B0 ise D .0250 n BY g A ORNEY United States Patent EXTENSIBLE PROP Boise D. Olson, Great Falls, Mont.

Application May 11, 1955, Serial No. 507,547

Claims. (Cl. 248-355) This invention relates to a novel mechanical jack or extensible prop, and has for its primary object to provide a jack or extensible prop which readily adapts itself for use in supporting structural members in overhead positions while being secured in place and which may also be utilized for effecting a lifting force on a member which is supported by the jack or prop.

More particularly, it is an aim of the present invention to provide an extensible prop which may be quickly and easily extended by gravity to approximately a desired length for use and which may thereafter be further extended by a leverage force and additionally locked in its further extended position by the leverage means employed.

Still a further object of the invention is to provide an extensible prop having novel means for locking the prop in an extended position after effecting a final extension of the prop and whereby the extent that the prop is extended by operation of the locking means will be automatically varied in accordance with the limits to which the prop can be extended between the parts engaged by the ends thereof.

Still another object of the invention is to provide an extensible prop having novel means whereby the prop can be quickly released and extended by gravity for quickly adjusting the prop to an approximate length to fit between two surfaces to be engaged by the ends of the prop.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating a presently preferred embodiment thereof, and wherein:

Figure 1 is a fragmentary elevational view showing the prop in an applied position;

Figure 2 is a fragmentary longitudinal sectional view thereof, on an enlarged scale, taken substantially along a plane as indicated by the line 2-2 of Figure 1;

Figure 3 is an enlarged cross sectional view, taken substantially along a plane as indicated by the line 3--3 of Figure 2;

Figure 4 is an enlarged cross sectional view, taken substantially along a plane as indicated by the line 4--4 of Figure 2;

Figure 5 is an enlarged cross sectional view, taken substantially along a plane as indicated by the line 5-5 of Figure 2;

Figure 6 is a fragmentary detail longitudinal sectional view on an enlarged scale, taken substantially along a plane as indicated by the line 6-6 of Figure 2;

Figure 7 is a top plan view of one part of the extensible prop, shown removed, and

Figure 8 is a fragmentary vertical sectional view of the upper part of the prop, showing another form of article engaging detachable prop end.

Referring more specifically to the drawings, the extensible prop in its' entirety and comprising the invention is designated generally 10 and includes a body portion composed of telescopically interfitting parts, designated generally 11 and 12, each of which preferably comprises Patented Oct. 28, 1958 an elongated tube. The tubes 11 and 12 are of sufficient strength to sustain a pressure or weight of several hundred pounds and are preferably formed of a relatively lightweight metal, so that the prop 10 Will be sufficiently light in weight to be conveniently handled and used. The tube 12 has an external diameter substantially smaller than the internal diameter of the tube 11 to telescopically fit therein. An outer end 13 of the outer tube 11 has a ring 14 secured therein by suitable fastenings 15 and is provided with a centrally disposed threaded bore 16. A similar ring 14a of smaller outer diameter is secured in the outer end 17 of the inner tube 12 by similar fastenings 15a and has a central threaded bore 16a. A sleeve or bushing 18 is disposed in the other inner end of the outer tube 11 and has a flared end 19 which bears against the inner end 20 of the tube 11. Said bushing 18, as seen in Figure 7, has a gap 21 extending longitudinally therethrough forming a longitudinal groove or channel in the bushing when disposed in the tube end 20. The bore of the bushing 18 is sized to slidably receive and guide the inner tube 12 which is provided with a longitudinal extending rib 22 which slidably engages the longitudinal slot formed by the bushing gap 21 for non-turnably connecting the tubes 11 and 12. A guide collar 23 is preferably secured around the opposite inner end 24 of the inner tube 12 to insure axial movement of the inner tube relative to the outer tube and to additionally provide a stop for engagement with the bushing 18 to prevent disconnection of the tubes without first removing said bushing.

A split ring 25 is disposed around a part of the outer tube 11, at a point spaced from the ends thereof, and is suitably secured to the tube 11, as by Welding, as seen at 26. The split ring 25 preferably comprises complementary portions of a pair of bars having corresponding ends 27 which project outwardly from a part of the split ring 25 and which form a pair of spaced ears. The other ends 28 of the bars, forming the ring 25 and cars 27, extend in the opposite direction from the ring 25 and are disposed in abutting engagement with one another to provide a handle. The parts forming the handle 28 may be suitably secured together, as by fastenings 29.

An' elongated lever 30 has an inner end 31 which is swingably mounted between outer end portions of the ears 27 by a pivot element 32 which extends loosely therethrough and through said ears 27. The lever 30 normally extends from its pivot 32 toward the inner tube end 20 and is provided with an ear or extension 33 which projects from an inner edge 34 of the lever, near the end 31, and which is spaced from the ears 27. The other end of the lever 30 forms a handle 35.

An elongated housing, designated generally 36, includes an elongated base section 37 and a removable cover section 38. The base section 37 is disposed against a longitudinal portion of the outer tube 11 and is transversely bowed, as seen in Figure 4, to conformably engage thereagainst and is secured thereto by fastenings 39, one of which additionally secures the bushing 18 in the tube end 20. The base section 37 has outwardly turned back longitudinal edge portions forming inwardly opening grooves 01' channels 4:) for slidably receiving outturned side edge portions 41 of the cover 38. The cover 38 has an open end 42, defining an open end of the housing 36, which is disposed adjacent the tube end 20, and a closed opposite end 43, which abuts against the end of the base 37 which is disposed remote from the open housing end 42. One end of a pull spring 44 which is loosely disposed longitudinally in the housing 36 is anchored to an eye fastening 45 which is fixed to the base 37 adjacent the end wall 43.

A gripping plate 46 of substantial thickness has an opening 47 through which the tube 12 loosely extends, as best seen in Figure 2. Plate 46 has a notch 47a through which rib 22 loosely extends. An eye fastening 48 is connected to a part of the plate 46 which is spaced from the opening 47 and is connected to the other end of the spring 44 for connecting the plate to said spring beneath the open end 42 of the housing 36. The housmg 36 is disposed on a side of the tube 11 remote from the side thereof adjacent which the lever is disposed. Another part of the plate 46, which is disposed remote from the fastening 48, has a pair of spaced ears 49 secured thereto and projecting from the side thereof which is disposed adjacent the tube end 20.

An extensibly adjustable connecting linkage 50 has one end pivotally connected by a fastening 51 to the lever ear 33 and an opposite end loosely disposed between the ears 49 and pivotally connected thereto by a fastening 52. The linkage 50 preferably includes a pair of eye screws 53 and 54 constituting end portions thereof, the remote ends of which are connected to the fasten lngs 51 and 52, and a turnbuckle 55 the ends of which threadedly engage the adjacent threaded shank ends of said screws 53 and 54. The turnbuckle 55 is turnable for extending or retracting the screws 53 and 54 relative to one another, in a conventional manner, for varying the spacing between the fastenings 51 and 52.

A leaf spring 56 has one end disposed between and clamped to a pair of clamping strips 57 by fastenings 58 which extend through said strips 57 and said spring end and which are anchored in the outer tube 11 for mounting the leaf spring 56 longitudinally of the outer tube. The strips 57 are disposed between the ears 27 and the tube end 13 and adjacent said ears. The unsecured end of the leaf spring 56 extends between the cars 27 and is disposed between the lever end 31 and the tube 11 to bear against an inner edge portion 34a of the lever end 31 to retain said lever 30 in its position of Figure 2 and with a straight edge portion 59 of the car 33 thereof abutting against the tube 11, between the cars 27 and the tube end 20.

A surface engaging unit 60 is illustrated in Figures 1, 2 and 3 and constitutes a detachable part of the prop 10. The surface engaging unit 60 includes a head 61 shown as a flat plate which may be of any desired size and which has a central boss 62 suitably fixed to an inner side thereof and from which projects a threaded stem 63 which is sized to threadedly engage in the bore 16 for mounting the unit 60 on the prop end 13. It will be readily apparent that the stem 63 may engage the threaded bore 160! for mounting the unit 60 beyond the tube end 17.

However, as illustrated in Figures 1 and 2, a cap or socket 64 formed of rubber or other suitable material is normally detachably mounted over the tube end 17. Figure 8 illustrates a gripping unit 60a which may be attached to either the end 13 or. 17 and which includes a gripping head 61:: in the form of a suction cup which may be of any desired size. The stem 63a which threadedly engages either the bore 16 or 16a extends through a collar or boss 62a and through an integral boss 61b which projects from the convex side of the suction cup 61a. The stem 63a preferably extends into the body of the suction cup 6101 and has a crosshead 63b which is embedded in the suction cup body. The collar or boss 62a is suitably secured on the stem 63a and against the outer end of the boss 6112. It is to'be understood that the attachments 60, 60a and 64 comprise only a few of the units which may be employed with the prop 10 as the end units may vary in shape, size and construction depending upon the parts to be engaged thereby.

One use of the prop 10 to which it is particularly well adapted is for supporting articles in overhead positions temporarily and while being secured, as for example in supporting sheet material such as ceiling board against a ceiling and while being secured thereto, as illustrated in Figures 1 and 2. For this use, the flat upper side of the attachment head 61 is placed against the underside of a piece of sheet material M while the sheet M is held against the ceiling or prior to raising the sheet M into a position against the ceiling. After the sheet M is positioned against the ceiling, the operator grasps the handle 28 to support the prop 10 with one hand and utilizes the other hand to grasp the lever handle 35 for swinging the lever 30 outwardly and upwardly about its pivot 32 from its position of Figure 2. This lever movement exerts an upward pull on the linkage 50 and on the portion of the plate 46 to which the ears 49 are secured for swinging said plate upwardly about the lower end of the spring 44 as a fulcrum into a plane substantially normal to the axis of the tubes 11 and 12. Diametrically opposite edge portions of the opening 47 are thus moved out of gripping engagement with the tube 12 which then slides downwardly by gravity, relative to the tube 11 and until the attachment 64 comes to rest on a supporting surface such as a floor portion F. The lever 30 is then swung downwardly and back to its position of Figure 2. Downward movement of the lever 30 displaces the linkage member 50 downwardly and thus exerts a downward thrust on the portion of the plate 46 to which the ears 49 are connected. This movement of the plate initially cants the plate to an angle relative to the axis of the tube 12, as seen in Figures 1 and 2, for causing diametrically opposite top and bottom edge portions of the opening 47 to grip portions of the tube 12, after which the plate 46 moves downwardly with the linkage 50 for further displacing the tubes 11 and 12 away from one another to thus further extend the prop 10 for tightly wedging said prop between the members F and M. This displacement of the canted plate 46 away from the tube end 20 is permitted due to the unique pivotal support of the plate 46 by the spring 44. This pivotal support additionally urges the plate toward a canted position whenever the plate is held canted by the lever 30 and linkage 50. Thus, the mounting and actuating means of the plate 46 initially functions as a jack to effect an extension of the prop 10, after which said parts function to effectively maintain the plate in gripping locked engagement with the tube 12 to prevent retraction of the prop until the lever 30 is again swung upwardly. As the lever 30 approaches its locked position of Figure 2, the pivot 51 of the linkage member 50 crosses a line intersecting the pivots 32 and 52 to thus lock the lever 30 in its position of Figure 2. Additionally, when the lever 30 reaches its position of Figure 2, in which it is held against further downward movement by its edge portion 59 engaging the tube 11, the leaf spring 56 assumes a position in engagement with the edge portion 34a to additionally assist in holding the lever 30 in its locked position of Figure 2.

The spring 44 also functions with the lever 30 and linkage means 50 to vary the distance that the prop is extended by the jacking action previously described. For example, if the prop cannot be extended the normal distance which will be accomplished by the jacking action, the spring 44 will yield and permit the plate 46 to slide downwardly relative to the tube 12 during the final portion of the downward and inward swinging movement of the lever 30 and before the plate 46 has been canted to the extent as shown in Figure 2, after which said spring will hold the plate 46 canted and in gripping engagement with the tube 12 in the locked position of lever 30, as seen in Figure 2. The pressure of the load borne by tube 11 is transmitted to the end of the plate 46 to which the ears 49 are connected through the lever portion disposed between the pivots 32 and 51, the linkage 50 and ears 49, which parts prevent any movement of said plate end relative to the tube 11, while the lever is in its locked position of Figure 2. At the same time, the spring 44 urges the other end of the plate 46 upwardly to maintain the plate canted and in frictional gripping engagement with the tube 12, so that tube 11 cannot move downward relative to tube 12 and tube 12 cannot be displaced upward relative to tube 11.

,It will also be readily apparent that the unit 60a may be employed to effect a gripping engagement of an end of the prop with the sheet M. It will likewise be obvious that other attachments may be utilized in lieu of the attachments 60, 60a and 64 of proper size and shape to most effectively fit and engage elements to be held thereby which elements may include pipes, beam members or the like. It will also be apparent that the prop 1b may be employed in a horizontal position. When so employed the tube 12 is initially extended by the spiral spring 65 which has sufficient tension to displace the tube 12 to substantially a fully extended position. The prop may also be employed at various angles relative to the horizontal and vertical. When the prop is only to be utilized in substantially an upn'ght position the spring 65 may be omitted.

Various other modifications and changes are contemplated and may obviously be resorted to, without departing from the function or scope of the invention as hereinafter defined by the appended claims.

l claim as my invention:

1. An extensible prop comprising an outer tubular member having an inner end and an inner member telescopically engaging in said outer member and extending from said inner end only thereof, a gripping member, yieldably extensible means connected to the outer tubular member and gripping member for swingably supporting said gripping member beyond and spaced from the inner end of said outer tubular member, said gripping member having an opening through which said inner member loosely extends, a lever, means swingably supporting said lever at one end thereof on said outer tubular member, a linkage member having one end pivotally connected to said lever at a point spaced from the lever pivot, means pivotally connecting the opposite end of said linkage member to said gripping member remote from the point at which the gripping member is swingably mounted, said lever being swingable away from the gripping member for exerting a pull on the linkage member for rocking the gripping member toward a position nor mal to the axis of said inner telescopic member to release and permit said inner telescopic member to slide freely through the opening of the gripping member and relative to the outer tubular member, said lever being swingable toward the gripping member to exert a thrust on the linkage member for initially rocking said gripping member into a canted position relative to the inner member and into gripping engagement therewith and for thereafter displacing said telescopic members away from one another.

2. An extensible prop as in claim 1, said yieldably extensible means permitting displacement of the gripping member away from the inner end of the outer tubular member for exerting an outward jacking force on the inner prop member when the lever is swung toward the gripping member.

3. An extensible prop as in claim 1, including spring means connected to said outer tubular member and bearing against a part of said lever and resisting swinging movement of the lever away from the gripping member when said lever is disposed adjacent the gripping member.

4. An extensible prop comprising elongated telescopically interfitting prop sections including an outer tubular section having an inner end and an inner section extending outwardly of the inner end of said outer section, a gripping member disposed beyond the inner end of said outer tubular section and having an opening through which the inner section loosely extends, means yieldably connect the gripping member to said outer member and on w rich said gripping member is swingably supported at a point spaced from the opening thereof, and limit and leverage means pivotally connected to the gripping member remote from the yieldable support thereof and pivotally connected to said outer tubular member at a point spaced from its inner end and movable in one direction for exerting a thrust on the gripping member to initially cant the gripping member relative to the axis of said inner section to cause the gripping member to frictionaliy grip said inner section and to thereafter exert a force on the gripping member for displacing the prop sections toward extended positions relative to one another, said link and lever means being movable in the opposite direction to move the gripping member to a released position in loose engagement with the inner section, said prop sections being held against retraction relative to one another solely by said gripping member when in a canted position, and said sections being freely movable relative to one another in either direction when the gripping member is in a released position.

5. An extensible prop as in claim 4, said means yieldably connecting the gripping member to said outer member comprising a contractial spring having one end secured to said outer membe an eye member anchored to and projecting from the gripping member toward said outer member and to which the opposite end of said spring is secured and by which said gripping member is swingably supported by said spring beyond the inner end of said outer member.

References Cited in the file of this patent UNITED STATES PATENTS 270,012 Eurruss M Jan. 2, 1883 737,713 Curtis a- Sept. 1, 1903 1,368,353 Roos Feb. 15, 1921 l,499,755 Stebbins July 1, 1924 1,681,192 McBride Aug. 21, 1928 1,686,079 Penneman Oct. 2, 1928 1,692,152 Bosco Nov. 20, 1928 2,653,785 La Russa Sept. 29, 1953 FOREIGN PATENTS l22,690 Australia Nov. 4, 1946 501,554 Great Britain Mar. 1, 1939 572,887 Germany Mar. 23, 1933 

